Background: Focal segmental glomerulosclerosis (FSGS) presents a range of potentially serious complications, including acute kidney injury (AKI), infection and thromboembolism. This study aimed to find out the incidence rates and risk factors for these complications in FSGS patients. Methods: Patients with biopsy-proven primary FSGS and nephrotic-range proteinuria were included in this study. A short-term (16-week) follow-up was performed to observe the aforementioned complications. Clinical characteristics of patients were recorded upon enrollment. AKI was diagnosed as an absolute increase in serum creatinine of >=0.3 mg/dL or a percentage increase of >=50% within 48 hours; infection, by a combination of clinical manifestations, laboratory tests and imaging examinations; and thromboembolism, by imaging methods. Risk factors for complications were evaluated by logistic regression model. Results: The study population included 90 FSGS patients (63 males, mean age 28.9 ± 12.9 years). The incidences of AKI, infection and thromboembolism were 44.4%, 25.6% and 12.2%, respectively. Patients with AKI were more likely to be male, with lower serum albumin, greater proteinuria and more severe acute tubulointerstitial damage. Patients with infection had higher proteinuria and lower serum albumin, globulin and IgG. Circulating endothelial cells (CECs) and von Willebrand factor were higher in patients with thromboembolism. Logistic regression showed that increased urine retinol-binding protein, decreased serum albumin and IgG, and increased CECs and hemoglobin were independent risk factors for AKI, infection and thromboembolism, respectively. Conclusions: AKI, infection and thromboembolism are common among FSGS patients. Awareness of risk factors and prevention of these complications are important for the prognosis of these patients.